If you wish to modify the time zone in cPanel Webmail, you may normally need to perform these basic steps.
Log in to cPanel: Take your cPanel login page for account access, type in your username and password.
Access Email Accounts: After logging in, go to the ‘Email Accounts’ tab. This is generally placed under the Mail or Email section according to your cPanel theme.
Select Email Account: Select the email account you wish to modify the time zone.
Change Time Zone: Search for any settings or preferences options relating to the email account in question. You should be able to locate the option for modifying the time zone pertaining to the account within these settings. This option may read any of these: "Preferences," "Settings," "Options."
Save Changes: Upon choosing the correct timezone, please ensure that you apply the changes effected. On that page, there should be a ‘Save’ or ‘Update’ button.